The aim of this study is to develop and examine the reliability and validity of the Japanese version of the European Organization for Research and Treatment of Cancer quality-of-life questionnaire-esophageal cancer (OES18) module for its use in Japan.Methods
We followed a two-phase process to translate the questionnaire, according to the guidelines of the European Organization for Research and Treatment of Cancer OES18. Phase 1: the first intermediary Japanese version was produced according to European Organization for Research and Treatment of Cancer quality-of-life unit translation project guidelines. The second intermediary version was the result of a backward translation project and two peer-to-peer discussion by healthcare professionals. Phase 2: the final Japanese version was produced after focus group discussions with team members and semistructured interviews.Results
Fifty patients with esophageal squamous cell carcinoma, who had undergone curative thoracic esophagectomy, participated in the study. The Japanese translated version of quality-of-life questionnaire-OES18 yielded cultural adaptation and validation scores whose reliability was confirmed by internal consistency tests. Convergent validity was moderate to high (from r = 0.671–0.903; P < 0.01), whereas discriminant validity was acceptably low. Significant reduction in pain-scale values was noted postoperatively in the thoracoscopic approach when compared with the thoracotomy approach (scale value: 9.62 vs. 12.71; P = 0.04).Conclusions
We developed the Japanese version of quality-of-life questionnaire-OES18. This module has good psychometric validity and recommended to assess the health-related quality of life in Japanese patients.